A variety of bicyclic N,N-disubstituted 2-aminopyridines have been prepared from diynes and cyanamides by nickel-catalyzed [2+2+2] cycloaddition reactions. The reactions proceeded at room temperature with low catalyst loading to afford 2-aminopyridines in good to excellent yields. The method is amenable to both internal and terminal diynes and proceeds in a regioselective manner. A number of cyanamides with diverse functional group tolerance were used. The intermolecular version employing 3-hexyne and N-cyanopyrrolidine also afforded the desired N,N-disubstituted 2-aminopyridine in good yield.

Nickel-Catalyzed [2 + 2 + 2] Cycloaddition of Diynes and Cyanamides. -The process affords 2-aminopyridine structures and is effective for reactions of internal as well as terminal diynes with a variety of cyanamides. In addition, a method that generates the Ni-carbene catalyst in situ from air-stable, readily available precursors is developed. -(STOLLEY, R. M.; MACZKA, M. T.; LOUIE*, J.; Eur. J. Org. Chem. 2011, 20-21, 3815-3824, http://dx.doi.org/10.1002/ejoc.201100428 ; Dep. Chem., Univ. Utah, Salt Lake City, UT 84112, USA; Eng.) -Bartels 49-151